-- Rollback (cancellation)
DELETE FROM employees WHERE employee_id = 123;    -- Done in current session
ROLLBACK;                                         -- Cancelled in current session
SELECT * FROM employees WHERE employee_id = 123;  -- Found
-- Commit (validation)
DELETE FROM employees WHERE employee_id = 123;    -- Done in current session
COMMIT;                                           -- Visible for ALL sessions
SELECT * FROM employees WHERE employee_id = 123;  -- Missing for ALL sessions